Acetabular cup positioners are used during total hip arthroplasty to assist the surgeon in positioning the prosthetic acetabular cup within the prepared acetabulum of the patient. Typically, the prosthetic cup will include a threaded central opening for accommodating a threaded stud of the cup positioner. An important process during positioning of the cup is to align the cup with the bodies anatomical axis to ensure proper function of the prosthetic joint. To assist the surgeon in aligning the cup, a wide multitude of sighting guides have been developed. Some of these sighting guides are removable to enable the positioner to be screwed off the acetabular cup once positioned.